1. Field of the Invention
The present invention relates to a progressive image signal compression coding method and apparatus, and more particularly, to a method and apparatus for compression-coding a frame divided into fields in which each field is processed using data only from itself, and fields in which each field is processed using a differential component between two fields within one frame.
2. Description of the Related Art
A conventional image signal compression coding method is performed using frames as basic units, that is, intra (I) frames in which each frame is compression-coded using information only from itself, predicted (P) frames in which a differential component detected from the previous I or P frames temporally preceding the present frame are compression-coded, and bidirectional predicted (B) frames in which a differential component detected from the previous I or P pictures or the following I or P pictures are compression-coded.
As described above, in the conventional image signal compression coding method, output data is formed using inter-frame information using frames as basic units. However, although such a compression coding method is useful in forming the output data using the inter-frame data information, the intra-frame data information cannot be utilized.
To solve the above problem, it is an objective of the present invention to provide an image signal compression coding method for coding one field by coding data from only that field, and coding the other field by coding a differential component between two fields within one frame.
It is another objective of the present invention to provide an image signal compression coding apparatus for coding one field by coding data from only that field, and coding the other field by coding a differential component between two fields within one frame.
Accordingly, to achieve the first objective, there is provided an image signal compression coding method comprising the steps of (a) compression-coding one field of an input progressive image signal composed of frames, using only data from that field, and (b) compression-coding the other field using differential data between the previous field and that field.
To achieve the second objective, there is provided an image signal compression coding apparatus comprising a pre-processor for outputting in an unaltered state data of one field of an input progressive image signal composed of frames, and outputting the other field as differential data between that field and the previous field, and a coder for generating coded data by performing compression coding on the output of the pre-processor.